Design and optimization of electrode-integrated microfluidic chips for enhanced electrochemical impedance spectroscopy assessments

Abstract Electrode-integrated microfluidic chips play a pivotal role in applying electrochemical impedance spectroscopy (EIS) across various domains. This technology has significantly transformed biomedical research, facilitating progress in drug discovery, diagnostics, and cell analysis. The architecture of these chips integrated with electrodes critically influences the precision and dependability of EIS outcomes. This study developed diverse microfluidic chip designs, including circular, deltoid, and deltoid-like shapes, to explore microenvironmental dynamics on EIS assessments. Moreover, computational fluid dynamics was utilized to examine the flow properties within the proposed chip designs by investigating the relationship between pressure and velocities in the microenvironment. The study also assessed the effects of varying flow rates (1, 10, 100 µ l) on EIS analysis and the simulation studies. Findings indicated that there were empty spaces in the circular design, which is commonly used, and it was not suitable for EIS experiments. Furthermore, it was noted that even with reduced altitude in the EIS measurement area, the environment remained conducive to more accurate measurements. A flow rate of 10 µ l min −1 was identified as optimal in this research, as it offered the best balance among charge transfer resistance ( R ct ), capacitance (Q), and open circuit potential values, while also minimizing the sample volume which is very important for microfluidic chip design and applications. This study demonstrated a strong interaction between microfluidic chip designs for electrode integration and EIS outcomes. On the other hand, it has yielded a reliable, cost-effective, rapid, practical, reusable, and portable platform after choosing an appropriate architecture for the electrode housing.